The first Easter egg on the list is the one that started it all. In 1980, Atari programmer Warren Robinett set about making a video game version of the original text Adventure. In the depths of the black castle in Games 2 and 3, which required special tools, direction, and a certain amount of know-how, players could maneuver to a room by the catacombs that had a single-pixel gray dot, the same color as the game’s background.